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C3d(g), iron nanoparticles, hemin and cytochrome c may induce oxidative cytotoxicity in tumors and reduce tumor-associated myeloid cells-mediated immunosuppression. Med Hypotheses 2022. [DOI: 10.1016/j.mehy.2022.110944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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2
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Rizzetto F, Mafra D, Barra AB, Pires de Melo G, Abdalla DSP, Leite M. One-Year Conservative Care Using Sodium Bicarbonate Supplementation Is Associated with a Decrease in Electronegative LDL in Chronic Kidney Disease Patients: A Pilot Study. Cardiorenal Med 2017; 7:334-341. [PMID: 29118772 DOI: 10.1159/000478733] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2016] [Accepted: 05/31/2017] [Indexed: 12/15/2022] Open
Abstract
Background Chronic kidney disease (CKD) patients develop metabolic acidosis when approaching stages 3 and 4, a period in which accelerated atherogenesis may ensue. Studies in vitro show that low pH may increase low-density lipoprotein (LDL) oxidation, suggesting a role for chronic metabolic acidosis in atherosclerosis. The present study attempted to evaluate the effects of conservative care using oral sodium bicarbonate (NaHCO3) supplementation on the electronegative LDL [LDL(-)], a minimally oxidized LDL, plasma levels in CKD patients. Methods Thirty-one CKD patients were followed by a multidisciplinary team during 15 months of care in which 1.0 mmol/kg/day oral NaHCO3 supplementation was first given in the third month. Blood samples were collected 3 months before the initiation of oral NaHCO3 supplementation (T1), at the time of the beginning of supplementation (T2), and thereafter, each 4 months (T3, T4 and T5) until month 15 of care. Blood parameters and LDL(-) were measured from these collections. Results After 12 months of conservative care, creatinine clearance (MDRD) was kept stable, and serum bicarbonate (HCO3-) increased from 20.5 ± 2.9 to 22.6 ± 1.1 mM (p < 0.003). LDL(-) plasma levels declined from 4.5 ± 3.3 to 2.1 ± 0.9 U/L (p < 0.007) after reaching mean serum HCO3- levels of 22.6 ± 1.1 mM. Conclusions Conservative care using oral NaHCO3 supplementation was able to stabilize renal function and decrease serum levels of LDL(-), a modified proatherogenic lipoprotein, only when mean serum HCO3- levels approached 22 mM. This study constitutes evidence that alkali therapy, in addition to its beneficial effect on renal disease progression, might serve as a preventive strategy to attenuate atherogenesis in CKD patients.
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Affiliation(s)
- Felipe Rizzetto
- Division of Nutrition, Federal Hospital of Lagoa (FHL), Rio de Janeiro, Brazil
| | - Denise Mafra
- Graduate Program in Cardiovascular Sciences, Federal Fluminense University (UFF), Niterói, Brazil
| | - Ana Beatriz Barra
- Division of Nephrology, Federal Hospital of Lagoa (FHL), Rio de Janeiro, Brazil
| | | | | | - Maurilo Leite
- Division of Nephrology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
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Yan LJ. Positive oxidative stress in aging and aging-related disease tolerance. Redox Biol 2014; 2:165-9. [PMID: 25460727 PMCID: PMC4297947 DOI: 10.1016/j.redox.2014.01.002] [Citation(s) in RCA: 120] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2013] [Revised: 12/30/2013] [Accepted: 01/01/2014] [Indexed: 12/14/2022] Open
Abstract
It is now well established that reactive oxygen species (ROS), reactive nitrogen species (RNS), and a basal level of oxidative stress are essential for cell survival. It is also well known that while severe oxidative stress often leads to widespread oxidative damage and cell death, a moderate level of oxidative stress, induced by a variety of stressors, can yield great beneficial effects on adaptive cellular responses to pathological challenges in aging and aging-associated disease tolerance such as ischemia tolerance. Here in this review, I term this moderate level of oxidative stress as positive oxidative stress, which usually involves imprinting molecular signatures on lipids and proteins via formation of lipid peroxidation by-products and protein oxidation adducts. As ROS/RNS are short-lived molecules, these molecular signatures can thus execute the ultimate function of ROS/RNS. Representative examples of lipid peroxidation products and protein oxidation adducts are presented to illustrate the role of positive oxidative stress in a variety of pathological settings, demonstrating that positive oxidative stress could be a valuable prophylactic and/or therapeutic approach targeting aging and aging-associated diseases.
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Affiliation(s)
- Liang-Jun Yan
- Department of Pharmacology and Neuroscience, and Institute for Aging and Alzheimer's Disease, University of North Texas Health Science Center, Fort Worth, TX 76107, United States.
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Shimizu Y, Nakazato M, Sekita T, Kadota K, Yamasaki H, Takamura N, Aoyagi K, Maeda T. Association between hemoglobin levels and arterial stiffness for general Japanese population in relation to body mass index status: The Nagasaki Islands study. Geriatr Gerontol Int 2013; 14:811-8. [DOI: 10.1111/ggi.12171] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/03/2013] [Indexed: 02/06/2023]
Affiliation(s)
- Yuji Shimizu
- Department of Community Medicine; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
- Department of Island and Community Medicine; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
| | - Mio Nakazato
- Department of Island and Community Medicine; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
| | - Takaharu Sekita
- Department of Island and Community Medicine; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
| | - Koichiro Kadota
- Department of Community Medicine; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
| | - Hironori Yamasaki
- Center for Health and Community Medicine; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
| | - Noboru Takamura
- Department of Global Health, Medicine and Welfare; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
| | - Kiyoshi Aoyagi
- Department of Public Health; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
| | - Takahiro Maeda
- Department of Community Medicine; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
- Department of Island and Community Medicine; Nagasaki University Graduate School of Biomedical Sciences; Nagasaki Japan
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Electronegative LDL: a circulating modified LDL with a role in inflammation. Mediators Inflamm 2013; 2013:181324. [PMID: 24062611 PMCID: PMC3766570 DOI: 10.1155/2013/181324] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Accepted: 07/19/2013] [Indexed: 12/13/2022] Open
Abstract
Electronegative low density lipoprotein (LDL(−)) is a minor modified fraction of LDL found in blood. It comprises a heterogeneous population of LDL particles modified by various mechanisms sharing as a common feature increased electronegativity. Modification by oxidation is one of these mechanisms. LDL(−) has inflammatory properties similar to those of oxidized LDL (oxLDL), such as inflammatory cytokine release in leukocytes and endothelial cells. However, in contrast with oxLDL, LDL(−) also has some anti-inflammatory effects on cultured cells. The inflammatory and anti-inflammatory properties ascribed to LDL(−) suggest that it could have a dual biological effect.
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Altaf N, Akwei S, Auer DP, MacSweeney ST, Lowe J. Magnetic Resonance Detected Carotid Plaque Hemorrhage is Associated With Inflammatory Features in Symptomatic Carotid Plaques. Ann Vasc Surg 2013; 27:655-61. [DOI: 10.1016/j.avsg.2012.10.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2012] [Revised: 09/25/2012] [Accepted: 10/11/2012] [Indexed: 01/17/2023]
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7
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Bian K, Murad F. Nitric oxide signaling in vascular biology. ACTA ACUST UNITED AC 2012; 1:17-29. [PMID: 20409830 DOI: 10.1016/j.jash.2006.11.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2006] [Accepted: 11/17/2006] [Indexed: 11/28/2022]
Abstract
Nitric oxide (NO) research has expanded rapidly in the past 20 years, and the role of NO in physiology and pathology has been extensively studied. This review focuses on the pathways of NO synthesis and metabolism in vascular biological systems. Healthy vascular homeostasis is dependent on the integrity of the endothelium, which is a very large dynamic autocrine and paracrine organ with vasodilator, anti-inflammatory, and antithrombotic properties. The importance and relevance of NO signaling is stressed in this review. The potential role of nitrotyrosine formation with vascular pathological conditions is discussed. The use of pharmacologic, biochemical, and molecular biological approaches to characterize, purify, and reconstitute these regulatory pathways should lead to the development of new therapies for various pathological conditions that are characterized by an insufficient production of NO. With more than 77,000 publications in the field of NO signaling, this brief review can only focus on some aspects of the field as it applies to vascular biology. Many molecular targets have been identified for drug development dealing with NO and cyclic guanosine monophosphate formation, metabolism, and function. Many agents have been identified that are in pre-clinical evaluation or in clinical trials. Certainly, many should prove to be important therapeutic additions during the next decade.
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Affiliation(s)
- Ka Bian
- The Institute of Molecular Medicine, The University of Texas-Houston Medical School, Houston, Texas, USA; The Murad Research Institute for Modernized Chinese Medicine and Shanghai University of Traditional Chinese Medicine, Shanghai, China; E-Research Institute of Nitric Oxide and Inflammatory Medicine of Shanghai Universities, Shanghai, China
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8
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Molecular and cellular mechanisms of macrophage survival in atherosclerosis. Basic Res Cardiol 2012; 107:297. [DOI: 10.1007/s00395-012-0297-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 08/20/2012] [Accepted: 08/26/2012] [Indexed: 01/22/2023]
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9
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Sánchez-Quesada JL, Estruch M, Benítez S, Ordóñez-Llanos J. Electronegative LDL: a useful biomarker of cardiovascular risk? ACTA ACUST UNITED AC 2012. [DOI: 10.2217/clp.12.26] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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10
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Lobo JC, Farage NE, Abdalla DSP, Velarde LGC, Torres JPM, Mafra D. Association between circulating electronegative low-density lipoproteins and serum ferritin in hemodialysis patients: a pilot study. J Ren Nutr 2012; 22:350-6. [PMID: 21741859 DOI: 10.1053/j.jrn.2011.05.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2011] [Revised: 05/02/2011] [Accepted: 05/03/2011] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Iron supplementation is a common recommendation to chronic kidney disease patients undergoing hemodialysis (HD). However, iron excess is closely associated with lipid peroxidation and, it is well known that electronegative low-density lipoproteins (LDL[-]) are present at higher plasma concentrations in diseases with high cardiovascular risk such as chronic kidney disease. Thus, the aim of this study was to investigate whether ferritin levels are associated with LDL(-) levels in HD patients. DESIGN This was a cross-sectional study. SETTING This study was conducted from a private clinic in Rio de Janeiro, Brazil. PATIENTS The study included 27 HD patients and 15 healthy subjects. METHODS AND PROCEDURES Twenty-seven HD patients (14 men, 58.6 ± 10 years, 62.2 ± 51.4 months on dialysis, and body mass index: 24.4 ± 4.2 kg/m(2)) were studied and compared with 15 healthy individuals (6 men, 53.8 ± 15.4 years, body mass index: 24.5 ± 4.3 kg/m(2)). Serum LDL(-) levels were measured using the enzyme-linked immunosorbent assay method; ferritin levels by commercially available kits, and tumor necrosis factor-α, interleukin-6, monocyte chemoattractant protein-1, and plasminogen activator inhibitor-1 were determined with a multiplex assay kit manufactured by R&D Systems. RESULTS The HD patients presented higher LDL(-) and tumor necrosis factor-α levels (0.15 ± 0.13 U/L and 5.9 ± 2.3 pg/mL, respectively) than healthy subjects (0.07 ± 0.05 U/L and 2.3 ± 1.3 pg/mL, respectively) (P = .0001). The mean ferritin level in HD patients was 1,117.5 ± 610.4 ng/mL, and 90% of patients showed ferritin levels exceeding 500 ng/mL. We found a positive correlation between LDL(-) and ferritin in the patients (r = 0.48; P = .01), and ferritin was a significant contributor to LDL(-) concentrations independent of inflammation. CONCLUSIONS Excess body iron stores for HD patients was associated with signs of increased oxidative stress, as reflected by increased LDL(-) levels in HD patients.
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Affiliation(s)
- Julie Calixto Lobo
- Institute of Biophysic Carlos Chagas Filho, Health Science Centre, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro-Rj, Brazil.
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Cheng TM, Mao SJT, Lai ST, Chang CC, Yang MC, Chen NC, Chou SC, Pan JP. Haemoglobin-induced oxidative stress is associated with both endogenous peroxidase activity and H2O2 generation from polyunsaturated fatty acids. Free Radic Res 2010; 45:303-16. [PMID: 21034361 DOI: 10.3109/10715762.2010.532492] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Patients with increased haemolytic haemoglobin (Hb) have 10-20-times greater incidence of cardiovascular mortality. The objective of this study was to evaluate the role of Hb peroxidase activity in LDL oxidation. The role of Hb in lipid peroxidation, H(2)O(2) generation and intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) was assessed using NaN(3), a peroxidase inhibitor, catalase, a H(2)O(2) decomposing enzyme and human umbilical vein endothelial cells (HUVECs), respectively. Hb induced H(2)O(2) production by reacting with LDL, linoleate and cell membrane lipid extracts. Hb-induced LDL oxidation was inhibited by NaN(3) and catalase. Furthermore, Hb stimulated ICAM-1 and VCAM-1 expression, which was inhibited by the antioxidant, probucol. Thus, the present study suggests that the peroxidase activity of Hb produces atherogenic, oxidized LDL and oxidized polyunsaturated fatty acids (PUFAs) in the cell membrane and reactive oxygen species (ROS) formation mediated Hb-induced ICAM-1 and VCAM-1 expression.
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Affiliation(s)
- Tsai-Mu Cheng
- College of Biological Science and Technology, National Chiao Tung University, Hsinchu, Taiwan, ROC
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12
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Lin HL, Zhang L, Liu CX, Xu XS, Tang MX, Lv HX, Li CJ, Sun HW, Zhang M, Hong J, Zhang Y. Haemin-enhanced expression of haem oxygenase-1 stabilizes erythrocyte-induced vulnerable atherosclerotic plaques. Br J Pharmacol 2010; 160:1484-95. [PMID: 20590638 DOI: 10.1111/j.1476-5381.2010.00799.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
BACKGROUND AND PURPOSE Previous studies demonstrated that intraplaque haemorrhage increased the contents of cholesterol and oxidants in atherosclerotic plaques. The present study was aimed to test the hypothesis that enhanced expression of haem oxygenase-1 (HO-1) may stabilize vulnerable plaques. EXPERIMENTAL APPROACH Intravascular ultrasound (IVUS) was performed to identify three similar abdominal aortic plaques in each of 58 fat-fed New Zealand rabbits after aortic balloon injury. With the guidance of IVUS, 50 microL autologous erythrocytes (RBC) or normal saline (NS) were injected from adventitia into two of the pre-selected plaques, respectively, whereas the third plaque served as a blank control. All rabbits were randomly divided into two groups, receiving intraperitoneal injection of haemin and saline respectively. KEY RESULTS Compared with NS or control plaques, RBC plaques had more macrophage infiltration and lipid content, thinner plaque fibrous cap, and higher expression of inflammatory factors and incidence of plaque rupture. RBC plaques in the haemin group had about a 50% lower incidence of plaque rupture than those in the control group. CONCLUSIONS AND IMPLICATIONS Haem oxygenase-1 may eliminate haem or other oxidants, exert unexpected anti-oxidative and anti-inflammatory effects and serve as a promising approach to the direct inhibition of erythrocyte-induced plaque instability.
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Affiliation(s)
- Hui Li Lin
- Shandong University Qilu Hospital, Jinan, Shandong, China
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13
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Laczik R, Szodoray P, Veres K, Lakos G, Sipka S, Szegedi G, Soltész P. Oxidized LDL induces in vitro lymphocyte activation in antiphospholipid syndrome. Autoimmunity 2010; 43:334-9. [PMID: 20187701 DOI: 10.3109/08916930903540440] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Oxidized low-density lipoprotein (oxLDL) is a key feature of the atheromatosus plaque and plays a critical role in foam cell formation and perpetuation of inflammatory processes. In antiphospholipid syndrome (APS), oxLDL molecules form complexes with beta2GPI and become target antigens for autoantibodies, which are detectable in the sera of these patients. oxLDL takes part in the pathogenesis of APS and in the concomitant accelerated atherosclerosis, yet the exact associated immune mechanisms are not clear in details. The aim of this study was to assess the activation and proliferation response of peripheral blood mononuclear cells (PBMCs) derived from patients with APS in the presence of oxLDL. Thirteen patients with APS and nine healthy individuals were enrolled in the study. Separated PBMCs of these patients were cultured in the presence of immunogenic epitope of oxLDL. Lymphocyte proliferation and cytokine secretion (TNF-alpha, IL-2, IFN-gamma, IL-4, and IL-10) were assessed by ELISA. We found significant PBMC proliferation in APS compared to healthy controls (PI/proliferation index/APS: 1.76 vs. PI control: 0.56; p = 0.032). A significant IL-2 and IFN-gamma secretion were detected upon oxLDL stimulus in patients with APS compared to controls (IL-2 cytokine secretion index (CSI) APS: 278.5, IL-2 CSI controls: 65.1; p = 0.025; IFN-gamma CSI APS: 163.2, IFN-gamma CSI controls: 77.4; p = 0.025). Based on our findings, we assume that oxLDL via Th1-type cytokine production and lymphocyte proliferation may contribute to the perpetuation of immune processes in APS.
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Affiliation(s)
- Renata Laczik
- Intensive Care Unit, 3rd Department of Medicine, Institute of Internal Medicine, University of Debrecen Medical and Health Science Center, Móricz Zs Street 22, 4004 Debrecen, Hungary.
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The role of red blood cells in the progression and instability of atherosclerotic plaque. Int J Cardiol 2010; 142:2-7. [DOI: 10.1016/j.ijcard.2009.10.031] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2009] [Accepted: 10/15/2009] [Indexed: 11/20/2022]
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Bian K, Doursout MF, Murad F. Vascular system: role of nitric oxide in cardiovascular diseases. J Clin Hypertens (Greenwich) 2008; 10:304-10. [PMID: 18401228 DOI: 10.1111/j.1751-7176.2008.06632.x] [Citation(s) in RCA: 151] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In contrast with the short research history of the enzymatic synthesis of nitric oxide (NO), the introduction of nitrate-containing compounds for medicinal purposes marked its 150th anniversary in 1997. Glyceryl trinitrate (nitroglycerin) is the first compound of this category. On October 12, 1998, the Nobel Assembly awarded the Nobel Prize in Medicine or Physiology to scientists Robert Furchgott, Louis Ignarro, and Ferid Murad for their discoveries concerning NO as a signaling molecule in the cardiovascular system. NO-mediated signaling is a recognized component in various physiologic processes (eg, smooth muscle relaxation, inhibition of platelet and leukocyte aggregation, attenuation of vascular smooth muscle cell proliferation, neurotransmission, and immune defense), to name only a few. NO has also been implicated in the pathology of many inflammatory diseases, including arthritis, myocarditis, colitis, and nephritis and a large number of pathologic conditions such as amyotrophic lateral sclerosis, cancer, diabetes, and neurodegenerative diseases. Some of these processes (eg, smooth muscle relaxation, platelet aggregation, and neurotransmission) require only a brief production of NO at low nanomolar concentrations and are dependent on the recruitment of cyclic guanosine monophosphate (cGMP)-dependent signaling. Other processes are associated with direct interaction of NO or reactive nitrogen species derived from it with target proteins and requires a more sustained production of NO at higher concentrations but do not involve the cGMP pathway.
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Affiliation(s)
- Ka Bian
- The University of Texas Health Science Center at Houston, The Brown Institute of Molecular Medicine, Houston, TX 77030, USA
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Naarmann IS, Harnisch C, Flach N, Kremmer E, Kühn H, Ostareck DH, Ostareck-Lederer A. mRNA silencing in human erythroid cell maturation: heterogeneous nuclear ribonucleoprotein K controls the expression of its regulator c-Src. J Biol Chem 2008; 283:18461-72. [PMID: 18441016 DOI: 10.1074/jbc.m710328200] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Erythroid precursor cells undergo nuclear extrusion and degradation of mitochondria when they mature to erythrocytes. It has been suggested before that the reticulocyte 15-lipoxygenase (r15-LOX) plays an important role in initiating the breakdown of mitochondria in rabbit reticulocytes. The expression of rabbit r15-LOX is regulated by the heterogeneous nuclear ribonucleoproteins (hnRNP) K and E1 at the translational level. However, this mechanism has never been confirmed in human erythropoiesis. Based on K562 cells we have set up an inducible human erythroid cell system. We show that, during induction, K562 cells exhibit changes in morphology and protein expression that are characteristic for terminal erythroid maturation: nuclear exclusion, expression of endogenous human r15-LOX regulated by hnRNP K and hnRNP E1, and loss of mitochondria. Importantly, induction of terminal erythroid maturation in primary human CD34(+) cells recapitulated the results obtained in K562 cells. Employing the physiologically relevant K562 cell system we uncovered a new mechanism of interdependent post-transcriptional regulation of gene expression. The timely expression of the tyrosine kinase c-Src, which phosphorylates hnRNP K in later stages, is controlled by hnRNP K in early stages of erythroid maturation. hnRNP K binds to the 3'-untranslated region of the c-Src mRNA and inhibits its translation by blocking 80 S ribosome formation. In premature erythroid cells, small interfering RNA-mediated knockdown of hnRNP K, but not of hnRNP E1, leads to the de-repression of c-Src synthesis.
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Affiliation(s)
- Isabel S Naarmann
- Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
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Lin HL, Xu XS, Lu HX, Li CJ, Tang MX, Sun HW, Zhang Y. Pathological mechanisms of erythrocyte-induced vulnerability of atherosclerotic plaques. Med Hypotheses 2008; 70:105-8. [PMID: 17601678 DOI: 10.1016/j.mehy.2007.04.020] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2007] [Accepted: 04/16/2007] [Indexed: 11/18/2022]
Abstract
Erythrocytes are considered a new culprit contributing to atherosclerosis. Plaques with intraplaque hemorrhage are prone to new plaque hemorrhage, which may not only stimulate the progression of atherosclerosis but also promote the transition from a stable to an unstable lesion. However, the role of erythrocytes in inducing the vulnerability of plaque with intraplaque hemorrhage and the possible mechanism involved are not well understood. Recently, increased cholesterol level from erythrocytes was reported to expand the lipid core of plaque. As well, heme, iron and phospholipids derived from erythrocytes trigger peroxidization in vitro, which is strongly associated with the progression of atherosclerosis. We speculate that erythrocytes trapped in plaque may induce vulnerability of atherosclerotic plaques not only by accumulating lipids but also by promoting peroxidization within plaques, thereby expanding the lipid core, increasing the infiltration of inflammatory cells and attenuating the fibrous cap of plaques. This proposition may provide clues into the development of novel treatments to increase the stability of atherosclerotic plaques.
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Affiliation(s)
- Hui-Li Lin
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Shandong University Qilu Hospital, Jinan, Shandong 250012, China
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Lin HL, Xu XS, Lu HX, Zhang L, Li CJ, Tang MX, Sun HW, Liu Y, Zhang Y. Pathological mechanisms and dose dependency of erythrocyte-induced vulnerability of atherosclerotic plaques. J Mol Cell Cardiol 2007; 43:272-80. [PMID: 17628589 DOI: 10.1016/j.yjmcc.2007.05.023] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2007] [Revised: 05/26/2007] [Accepted: 05/30/2007] [Indexed: 02/06/2023]
Abstract
To test our hypothesis that erythrocytes may induce plaque vulnerability and investigate the mechanism involved, we established a novel model of intraplaque hemorrhage in 56 New Zealand white rabbits with established plaques. Three distinct abdominal aortic plaques with similar thickness were identified in each rabbit with use of intravascular ultrasound (IVUS) imaging. Rabbits were equally divided into 4 groups depending on dosage of treatment; with the guidance of IVUS, one of the three plaques from each rabbit was injected from adventitia with autologous erythrocytes (RBC) or cholesterol (CH) for the following groups: RBC, 50 microL or 100 microL, and CH, 50 microL or 100 microL. One of the other two plaques in each rabbit received an equal volume of normal saline (NS) and one received no injection. Plaques in the 100 microL RBC group had a higher plaque rupture rate than its respective NS or blank controls plaques (57.1% vs. 14.3% or 14.3%, P<0.05). Plaques from the RBC or cholesterol groups showed, dose-dependently, more macrophage infiltration, more superoxide and lipid content, thinner plaque fibrous cap, higher mRNA level of MCP-1, IL-1 or IFN-gamma and higher vulnerability index than controls, especially in the RBC group. Thus, erythrocyte treatment can dose-dependently induce the vulnerability of plaques. Accumulation of lipid content and augmentation of oxidative stress and inflammation in the plaques are the probable pathological mechanisms involved.
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Affiliation(s)
- Hui-li Lin
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Shandong University Qilu Hospital, Jinan, Shandong, 250012, PR China
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Abstract
The role of nitric oxide (NO) in cellular signaling has become one of the most rapidly growing areas in biology during the past two decades. As a gas and free radical with an unshared electron, nitric oxide participates in various biological processes. The interaction between NO and proteins may be roughly divided into two categories. In many instances, NO mediates its biological effects by activating guanylyl cyclase and elevates intracellular cyclic GMP synthesis from GTP. However, the list of cGMP-independent effects of NO is also growing at a rapid rate. In this review, the importance and relevance of nitrotyrosine formation are stressed. The utilization of intact cell cultures, tissues, and cell-free preparations along with the use of pharmacological, biochemical, and molecular biological approaches to characterize, purify, and reconstitute these NO regulatory pathways could lead to the development of new therapies for various pathological conditions that are characterized by unbalanced production of NO.
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Affiliation(s)
- Ka Bian
- The Institute of Molecular Medicine, The University of Texas-Houston Medical School, Houston, TX 77030, USA.
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Szászi K, Jones JJ, Nathens AB, Lo AY, Marsden PA, Kapus A, Rotstein OD. Glutathione depletion inhibits lipopolysaccharide-induced intercellular adhesion molecule 1 synthesis. Free Radic Biol Med 2005; 38:1333-43. [PMID: 15855051 DOI: 10.1016/j.freeradbiomed.2005.01.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/09/2004] [Revised: 11/29/2004] [Accepted: 01/20/2005] [Indexed: 01/18/2023]
Abstract
Cellular redox status is known to regulate a number of biological processes, including the activation of inflammatory genes. Our previous studies demonstrated that thiol depletion using diethyl maleate (DEM) reduced neutrophil sequestration in animal models of inflammation, an effect primarily mediated by impaired upregulation of the adhesion molecule, ICAM-1. The present studies were performed to discern the mechanism whereby DEM prevents LPS-induced ICAM-1 expression in human umbilical vein endothelial cells. DEM caused a time- and concentration-dependent inhibition of ICAM-1 expression in LPS-stimulated HUVEC by blocking induction of gene transcription. Interestingly, DEM had little effect on the degradation of the inhibitory protein IkappaB-alpha, but rather appeared to prevent translocation of the transcription factor NF-kappaB into the nucleus. Readdition of glutathione following DEM treatment restored the ability of LPS to induce NF-kappaB translocation and ICAM-1 synthesis. DEM plus LPS caused synergistic induction of heme oxygenase-1 (HO-1), suggesting its role in the inhibitory effects of DEM. However, HO-1 was shown to be neither sufficient nor necessary for the anti-inflammatory effects of glutathione depletion. These studies illustrate that thiol depletion may represent a potential therapy for inflammation, exerting its effects via a distinct mechanism on cell signaling pathways.
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Affiliation(s)
- Katalin Szászi
- Department of Surgery, University Health Network and University of Toronto, 200 Elizabeth Street, Toronto, Ontario, Canada M5G 2C4
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Takahashi H, Nishina A, Fukumoto RH, Kimura H, Koketsu M, Ishihara H. Selenoureas and thioureas are effective superoxide radical scavengers in vitro. Life Sci 2005; 76:2185-92. [PMID: 15733933 DOI: 10.1016/j.lfs.2004.08.037] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2004] [Accepted: 08/18/2004] [Indexed: 10/25/2022]
Abstract
Oxygen radicals, such as superoxide radicals, embellishing DNA, protein, lipids, etc., and carrying out the obstacle of the function of a cell is known. It depends for the oxidant level in the living body on the balance of a generation system and an elimination system of oxygen radicals, and research which controls an oxidant level in the living body is briskly done by taking in the substance which eliminates an oxygen radical. We investigated scavenging effects of superoxide radicals by selenoureas and thioureas using a highly sensitive and quantitative chemiluminescence method. At 330 nM, five selenoureas and five thioureas scavenged fractions of superoxide radicals (O2-) ranging from 8.4% to 87.6%. Among five N,N-unsubstituted selenoureas and N,N-unsubstituted thioureas 1-selenocarbamoylpiperidine and 1-thiocarbamoylpyrrolidine were the most effective scavengers. A possibility that selenoureas could use it as a new superoxide anion-scavenging substance from the result of this research became clear.
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Affiliation(s)
- Hitoe Takahashi
- Gunma Industrial Technology Center, 884-1 Kamesato, Maebashi, Gunma, 379-2147, Japan
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22
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Takahashi H, Nishina A, Fukumoto RH, Kimura H, Koketsu M, Ishihara H. Selenocarbamates are effective superoxide anion scavengers in vitro. Eur J Pharm Sci 2005; 24:291-5. [PMID: 15734295 DOI: 10.1016/j.ejps.2004.11.004] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2004] [Revised: 11/03/2004] [Accepted: 11/08/2004] [Indexed: 11/23/2022]
Abstract
We investigated the superoxide anion-scavenging effects of six selenocarbamates and four thiocarbamates, using a highly sensitive quantitative chemiluminescence method. At 333 nM, six selenocarbamates and four thiocarbamates scavenged in the range of 2.9-68.7% of O(2)*-. Se-methyl N-phenylselenocarbamate and Se-methyl N-(4-methylphenyl)selenocarbamate exhibited the strongest superoxide anion-scavenging activity among the Se-selenocarbamates. In contrast, the corresponding S-thiocarbamates had moderate inhibitory effect. The 50% inhibitory concentrations (IC(50)) of Se-methyl-N-phenylselenocarbamate and Se-methyl-N-(4-methylphenyl)selenocarbamate were determined to be 140 nM and 162 nM, respectively. Thus, these compounds acted in vitro as effective and potentially useful O(2)*- scavengers.
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Affiliation(s)
- Hitoe Takahashi
- Gunma Industrial Technology Center, 884-1 Kamesato, Maebashi, Gunma 379-2147, Japan
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23
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Sekiguchi A, Nishina A, Kimura H, Fukumoto RH, Kanoh K, Ishihara H, Koketsu M. Superoxide Anion-Scavenging Effect of 2-Amino-1,3-selenazoles. Chem Pharm Bull (Tokyo) 2005; 53:1439-42. [PMID: 16272727 DOI: 10.1248/cpb.53.1439] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We investigated the superoxide anion scavenging effects of thirteen 2-amino-1,3-selenazoles using a highly sensitive quantitative chemiluminescence method. At 166 microM, the 2-amino-1,3-selenazoles scavenged in the range of 14.3 to 96.7% of O2-. 2-Piperidino-1,3-selenazole and 4-phenyl-2-piperidino-1,3-selenazole exhibited the strongest superoxide anion-scavenging activity among the 2-amino-1,3-selenazoles. The 50% inhibitory concentrations (IC50) of 2-piperidino-1,3-selenazole and 4-phenyl-2-piperidino-1,3-selenazole were determined to be 4.03 microM and 92.6 microM, respectively. Thus, these compounds acted in vitro as effective O2- scavengers.
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24
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Takahashi H, Nishina A, Kimura H, Motoki K, Koketsu M, Ishihara H. Tertiary selenoamide compounds are useful superoxide radical scavengers in vitro. Eur J Pharm Sci 2004; 23:207-11. [PMID: 15489121 DOI: 10.1016/j.ejps.2004.04.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2003] [Revised: 04/06/2004] [Accepted: 04/21/2004] [Indexed: 10/26/2022]
Abstract
We investigated the scavenging effects of tertiary selenoamide compounds for super oxide radicals using a highly sensitive and quantitative chemiluminescence method. At 333 nM, tertiary selenoamide compounds scavenged 25.8-81.6% of O(2)(-). N-(Phenylselenocarbonyl) piperidine was the most effective scavenger of superoxide radicals. While N,N-diethyl-2-selenonaphthylamide and N,N-diethyl-4-chloroselenobenzamide was a moderately effective scavenger of superoxide radicals. The IC(50) of N-(phenylselenocarbonyl) piperidine and N,N-diethyl-2-selenonaphthylamide were determined to be 110 and 182 nM, respectively. The results suggest that tertiary selenoamide compounds are useful scavengers of superoxide radicals.
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Affiliation(s)
- Hitoe Takahashi
- Gunma Industrial Technology Center, 884-1 Kamesato, Maebashi, Gunma 379-2147, Japan
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Klouche K, Morena M, Canaud B, Descomps B, Beraud JJ, Cristol JP. Mechanism of in vitro heme-induced LDL oxidation: effects of antioxidants. Eur J Clin Invest 2004; 34:619-25. [PMID: 15379761 DOI: 10.1111/j.1365-2362.2004.01395.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
BACKGROUND Heme protein toxicity, owing to generation of reactive oxygen species most likely by direct interaction between heme iron and hydrogen peroxide (H2O2), may be involved in various pathologies, including atherogenesis and pigmentary acute renal failure. The aim of this study was to investigate the mechanism of heme cytotoxicity and the effects of antioxidant therapies in an in vitro model of heme-induced low-density lipoprotein (LDL) oxidation. MATERIALS AND METHODS Human LDLs were exposed to heme, iron (Fe), protoporphyrin (PPIX) and PPIX-Zinc (Zn) with or without H2O2. Lipid peroxidation was monitored by measurement of conjugated diene formation (at the 234-nm absorbance). The effect of various antioxidants, such as vitamin E and vitamin C, reduced glutathione (GSH), and oxidized glutathione (GSSG), mannitol and desferoxamine (DFO) was further investigated in the established in vitro model of LDL oxidation. RESULTS Incubation of LDLs in the presence of heme/H2O2 induced lipid peroxidation with the optimal oxidation rate being at 5 microm heme/100 microm H2O2 doses. By contrast, incubation of LDL with H2O2, Fe, Fe/H2O2, PPIX, PPIX/H2O2, heme or PPIX-Zn did not initiate any LDL oxidation. In vitro, the vitamin E load protected native LDLs against heme/H2O2 oxidative modifications. Incubation of LDLs with increasing doses of vitamin C, GSH and DFO conferred a dose-dependent protection, while mannitol and GSSG had no effect. CONCLUSIONS Initiation and propagation of heme-induced lipid peroxidation is not mediated by a Fenton reaction but depends on specific interactions between heme and H2O2. It may result from the generation of ferryl and perferryl radicals derived from hemic Fe and H2O2 interactions. A protective effect of vitamins E, C, GSH and DFO was demonstrated in this model.
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Affiliation(s)
- K Klouche
- Lapeyronie University Hospital, Montpellier, France.
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Abstract
PURPOSE OF REVIEW The occurrence in blood of an electronegatively charged LDL was described in 1988. During the 1990s reports studying electronegative LDL (LDL(-)) were scant and its atherogenic role controversial. Nevertheless, recent reports have provided new evidence on a putative atherogenic role of LDL(-). This review focuses on and discusses these new findings. RECENT FINDINGS In recent years, LDL(-) has been found to be involved in several atherogenic features through its action on cultured endothelial cells. LDL(-) induces the production of chemokines, such as IL-8 and monocyte chemotactic protein 1, and increases tumor necrosis factor-alpha-induced production of vascular cell adhesion molecule 1, with these molecules being involved in early phases of leukocyte recruitment. LDL(-) from familial hypercholesterolemic patients also decreases DNA synthesis and intracellular fibroblast growth factor 2 production, which may contribute to impaired angiogenesis and increased apoptosis. In addition, the preferential association of platelet-activating factor acetylhydrolase with LDL(-) has been reported, suggesting a proinflammatory role of this enzyme in LDL(-). SUMMARY Recent findings suggest that LDL(-) could contribute to atherogenesis via several mechanisms, including proinflammatory, proapoptotic and anti-angiogenesis properties. Further studies are required to define the role of LDL(-) in atherogenesis more precisely and to clarify mechanisms involved in endothelial cell activation.
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Affiliation(s)
- José Luis Sánchez-Quesada
- Biochemistry Department and Research Institute, Hospital de la Santa Creu i Sant Pau, C/Antoni Maria Claret 167, 08025 Barcelona, Spain
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